Ok, on closer inspection, the current logic is: the NIC reports
carrier detect nearly instaneously and thus its carrier detect
reporting is considered unreliable. Rather than immediately sending
packets, we wait for some interval for it to really be up so that the
backlog of console messages doesn't get pumped into the bit bucket.
So I'm going to change it from "flaky" to "untrustworthy" and add a
comment.

Why don't you trust an instaneously available carrier? Any
reason to assume there will be false positives?
Regards
Patrick